<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <h1>jsonp</h1>
  <button id="btn">发送jsonp请求</button>
  <script>
    function callback(data) {
      console.log("callBack执行了,参数是:", data)
    }

    const oBtn = document.getElementById('btn');
    let oScript = null;
    oBtn.onclick = function () {
      if (oScript) {
        // document.body.removeChild(oScript);
        // 删除某个元素
        oScript.remove();
      }
      oScript = document.createElement("script");
      oScript.src = "http://127.0.0.1:3000/getUser?userId=001&cb=callback";
      document.body.appendChild(oScript)
    }
  </script>

  <script>
    // callback("hello")
    // callback(data)
    // callback({code:10000,msg:'chenggong'})
  </script>
</body>

</html>